The new photography
Daily National Republican (Washington, DC) December 23, 1864
Among the remarkable discoveries that have made the last hundred years — a remarkable century — is that of photography, one of the most absolutely new revelations of all that have come upon many generations past and passing.
The basic processes
The keystone to photography is the sensitiveness of certain compounds of silver to the action of light.
No other metal but silver serves for the purposes of photography. The chloride of silver, although it remains stable in the dark, is separated into the chlorine of silver if exposed to the light; the bromide and iodide, under some conditions, is similarly affected by light.
This tendency of silver, or “salts of silver,” to escape from these compounds when exposed to light is the foundation of sun picturing.
The escaped silver when separated by light from iodine or bromine, in which it was combined, is blackish-brown or purple, and with this, the sun paints his picture.
“Wherever his ray falls upon a sensitive silver salt,” says a writer familiar with this subject, “there, after a time, the mark of its presence is left in a patch of black silver, and the mass of this silver is greater or less according to the length of time during which a ray of light has fallen on it.
The camera — a new contraption
“The photographic process, in its simplest form, consists in simply guiding the incidence of this ray. A plate covered with a sensitive salt of silver is put upright in a dark box known as the ‘camera,’ which has a round hole at the other end, and in this round hole is screwed a lens.
“The lens throws upon the plate a picture of the objects opposite to it, and each of those objects leaves its mark of reduced silver upon the plate. Those which reflect much light, such as the sky, or a white dress, leave a very dark mark; those which reflect less light leave a less decided mark, and those which reflect little or no light leave no mark at all.
“Thus the rays of light describe in monochrome a complete picture upon the sensitive salt of silver; only it is a picture with this peculiarity — that everything white is represented black, and everything black is left white.”
The process of “developing” the picture must be carried on in a room from which the light of day is carefully excluded. Most commonly the delicate manipulation is done by gaslight, but in Mr Gardner’s establishment, a window of peculiar color admits light from which the chemical rays are extracted by the stained glass, or, to speak more properly, perhaps, the rays of light which act chemically upon the plate are absorbed by the medium through which it is made to pass.
This is the simplest process of photography, but more complicated modifications are introduced to render the art practical. It is found that if a sensitive plate is exposed but a few seconds, the silver undergoes sufficient change to enable the manipulator to remove the salts unaffected by the light by means of chemicals.
Proto-sulfate of iron is now the most approved agent for developing the picture, and the sensitive plate is now prepared with two salts of silver, bromide and iodide, instead of the iodide alone.
It would require columns to explain the various difficulties of the photographer’s delicate task in preparing the “negative,” as the silver picture fixed upon the glass plate is called.
Printing the photograph
After the negative is prepared, the process of printing the picture from it is comparatively simple. The negative is exposed to the sun with a piece of paper, sensitized with chloride of silver, under it.
The sun streaming through the bare glass of the negative, paints in reduced silver the shadows of the picture upon the paper beneath. Acting with less force through the translucent parts of the silver deposit upon the negative, he fills in the half-tone of the picture; and leaving untouched those parts which lie under the opaque portions of the negative, he leaves the natural color of the paper to supply the high lights.
The picture, which is tawny red when “printed,” is toned by chemical applications, and at length comes forth the perfect production we see in the albums and frames that ornament our parlors.
One of the most complete photographic establishments in this or any other country, without doubt, is that of Mr Gardner, just finished, in Seventh Street, near D Street.
The building was constructed from the start for the business of photography, and no detail necessary in the practical working of the process has been neglected.
Skylights and operating rooms for ladies and gentlemen are prepared with all the necessary appliances, ample accommodations for the artists engaged in finishing the pictures are provided, and, in short, nothing that is requisite for the production of photographic pictures in their greatest perfection has been neglected.
Mr Gardner’s skill as a photographic artist has been attested for years by his portraits and his war pictures, and now that he has an establishment the most perfect and extensive of its kind, we shall expect to see corresponding results from his artistic labors.
Mr M B Brady, who has a worldwide reputation for his skill in the photographic art, has a branch establishment in this city where pictures are taken perfection.
Either of these gentlemen will probably explain to those who call upon them in many particulars respecting photography, which we are unable to give, our object having been only to interest our readers in the scientific principles by which such beautiful results are produced.